Gun perforator



5 Sheets-Sheet l MN NNN N2 a m GUN PERFORATOR M. SCHLUMBERGER Filed Jan. 2s. 1940 Aug. 7, 1945.

Sw TN 3,

. Y@ MW M. SCHLUMBERGER 2,381,081

Aug. 7, 1945.

GUN PERFORATOR Filed Jan. 23, 1940 5 Sheets-Sheet 2 ffy 153" 10 151' T51/'f4 140 1575 158155515913 gc V l/gr/ "Z6/141 115,45 111 142 154 155 152 165 235 159 150 1NVENTOR.

- /Vdra//Jr/umkr fr ATTORNEYS Aug. 7, 1945, M. SCHLUMBERGER 2,381,081

GUN PERFORATOR Filed Jan. 23, 1940 5 Sheets-Sheet 5 Marcel Sdi/Iwzr BY W27 .10 ATTORNEYS Aug. 7, 1945.' M. sczHLuMBERGERy 2,381,081

GUN PERFORATOR Filed Jan. 25, 1940 5 sheetssheet 4 18 M15@ 161 559 gm je 201 jg (00 196 jgg Tl". Z3

21g 7' Z4 i- 2f 155 4 220 217 1M 1g 221 g2g ZZ! 152 183 INVENTOR 222 156/4412# /dufahrfg .zza

2.97 Z50 zal 22616; 157 da?. www

ATTORNEYS M. SCHLUMBERGER GUN PERFORATOR Aug. 7, 1945.

Filed Jan. 23, 1940 5 Sheets-Sheet 5 INVENTOR:

A TORNEYS Patented Aug. 7, 1945 2481.081 GUN'rnnFoaA'ron Marcel Schlumberger, Paris, France: vested in thi Alien Property Custodian Application January 23, 1940. Serial No. 315,157

- In France February 2, V193!) 25 Claims. (Cl. 16k-0.5)

The present invention relates to firing devices,

and more particularly to new and improved apparatus for perforating metallic casings. such as, for example, are used in oil wells.

A primary object of the invention'is to provide apparatus for perforating metallic casings which is characterized by simplicity in handling and increased safety of operation.

Another object of the invention is to provide perforating apparatus which comprises a plurality of vinterchangeable gun units which may be conveniently assembled to form a perforator of the desired character.

A further object of the invention is to provide periorating apparatus having a simplified electrical circuit for ring the gun units of the system.

One feature of the invention resides in the provision of metal perforator units of elongated shape having at least two longitudinal powder chambers formed in the peripheral portion thereof, with at least one barrel hole extending from each chamber to the lateral wall of the unit and passing through the central portion thereof.

Another feature of the invention consists in providing a perforator structure including an assembly of a plurality of units mounted end to end in series without any common support, each of the units being provided with powder ignition means, adapted to be automatically interconnected from one unit to the next one upon assembly of the series oi units so as to constitute at least one ignition circuit extending therethrough.

According to still another feature of the invention, thepowder for each chamber is contained in a cartridge adapted to lit therein and each unit is provided with extracting means for simultaneously removing all the cartridges in the unit from the! respective chambers, when it is detached 4from he adjacent one.

In an embodiment of the invention, each powder chamber contains one cartridge and the powder in the successive cartridges is ignited by electric means. f u In another embodiment, corresponding cartridge chambers of the successive units are adapted to communicate with one another in series and the combustion of the iirst cartridge of a series produces the successive'ignition of the other cartridges thereof with the interposition of ignition delaying means, so as to ensure a suiiicient interval of time between'the ring of two consecutive cartridges.

According to an embodiment ofthe .present invention, the connection between eachchamber and the next one is inclined with respect tothe axial direction of the apparatus so that the successive cartridges oi the series being red are According to still another embodiment of the sists in the provision of a switch automatically'- operated by the iii-ing of each cartridge, which present invention, the apparatus includes| in series with the electrical circuit, a circuit breaker which, each time a cartridge is fired/is adapted' to be operated for the purpose of interrupting, for verification purposes, the current owins through an indicating circuit.

Still another embodiment of the invention con switch is interconnected with the electrical means for firing the cartridges in such a manner that the successive cartridges ignited are located on a helix instead of being located on a straight line parallel to the axis. y.

Other features of the present invention will become apparent from the following detailed description of several specic embodiments taken with reference to .the appended drawings, in which:

Fig. 1 is a view in elevation of a perforating gun constructed in accordance with the present invention;

Fig. 2 is an end view of the gun shown in Fig. 1;

Fig. 3 is a view in longitudinal section of a portion of the peri'orator of Fig. 1 taken along the line 3 3 of Fig. 2;

Fig. 4 is a view in transverse section taken along the line i-d oi Fig. 3;

Fig. 5 is a view in transverse section taken alon the line 5--5 oi Fig. 3;

Fig. 6 is a sectional view of a vcartridge constructed according to the present invention;

Fig. 7 is a sectional view of a modined form of cartridge;

Fig. 8 is a view in section taken along line 8-8 of Fig. 7;

Fig. 9 is a view in section taken along line 9-8 of Fig. l0 and illustrating a modiiled form of' perforator unit:

`ling. 10 is a sectional view taken along line lli-I0 of Fig. 9:

Fig. 11 is aview in transverse section illustrating another modiiled form `of perforator unit;

Fig. 11A is a view in section taken along line IIA-l tAofFig. 11;

Fig. 12 is a view in longitudinal section of a head unit provided with an automatic circuit breaker for verification purposes;

Fig. 13 is a Jview in longitudinal section taken along line I3-I3 of Fig. 13A, illustrating still another form of perforator element;

Fig. 13A is a left end view oi the periorator unit 24 shown in Fig. 13 with the cartridges in position in the cartridge chambers therein;

Fig. 14 .is another sectional view taken along line Il-i4 of Fig. 13A, showing a cartridge'inserted in position, and illustrating the iirlng circuit therefor;

Fig. i5 is a view in longitudinal sectiontaken along line IBL-Il of Fig. 16 of a modified form of perforator unit in which a cartridge is adapted to be ignitedV by the powder gases from a cartridge in a preceding unit;

Fig. 16 is a front end view of the perforator unit shown in Fig. 15;

Fig. 17 is a view in longitudinal section of a further modied form of perforator unit;

Fig. 18 is a sectional view taken along line I8-I8 of Fig. 17:

Fig. 19 is a sectional view taken along line IS--I-S of Fig. 17:

Fig. 20 is a plan view of a detail of the unit shown in Fig. 17;

Fig. 21 is a view in section taken along line 2I-2I of Fig. 20:

Fig. 22 is a view in longitudinal section of a head unit provided with a switch for controlling the order of ignition of the cartridges in the perforator units;

Figs. 23, 24 and 25 are also views in longitudinal section of further modifications of the head unit shown in Fig. 22;

Fig. 26 is a schematic diagram illustrating the electrical firing circuits for the gun perforator shown in Fig. i:

Fig. 27 is a view in longitudinal section illustrating electrical means for igniting the first of a group of cartridges like the cartridge shown in Fig. 7; and

Fig. 28 is a view in longitudinal section illustrating mechanical means for firing the iirst of a group of cartridges like the cartridge shown in Fig. 7.

Considering Fig. 1, the gun perforator comprises a plurality of interchangeable perforating units I0, I and I0", threadedly secured to one another. The lowermost perforator unit I0" is connected to an end piece I l to which is secured a rubber guiding member I2 provided with a plurality of radial ins I3 which serve to maintain the perforator in a substantially central position in a bore hole.

The uppermost perforator unit lll is threadedly connected to a head piece I4, including a guide member I5 for the cable i6 on which the perforator assembly is adapted to be suspended in a bore hole, a coupling member il and two separable connector units I8 and I9. Within the units I8 and I9 is contained apparatus for connecting the electrical circuits of the perforator elements Ill, I0' and I0" to the various conductors in the cable I6 as will be described in greater detail hereinafter.

Inasmuch as the perforator units Ill, I0 and IIJ" are identical in construction, it will be sufficient to describe only the perforator unit Il) in detail. Corresponding parts on the units i9' and l0" will accordingly be designated by the corresponding primed or double primednumbers, respectively.

Referring to Fig. 3, the perforator unit I0 may comprise, for example, a cylindrical unit provided with three cartridge chambers 20, two of which are shown in the gure, which are disposed parallel to the axis of the unit and the axes of which pass through the apices of an equilateral triangle located in a plane at right angles to its axis. Each chamber 20 is provided with a lower tapered portion 2l terminating in a small passage 22 in the lower face of the unit I0.

In this embodiment of the invention each cartridge chamber 20 is provided with a barrel hole 23 passing through the axis of the unit and extending from each chamber 20 to the external Wall of the unit diametrically opposed thereto.

'Ihe barrel holes 23 are preferably located in three different transverse planes as shown in Fig. 4. Within the barrel holes 23 are inserted the bullets 239 which are held'in position by suitable plugs 240 which also serve to prevent the inilow of water into the chambers 2U.

The unit I0 is provided at oneend with an internally threaded skirt portion 24 and at the other end with an externally threaded portion 25 of reduced diameter, whereby it may be secured to the adjacent perforator units constituting the apparatus. A recess 26 is provided inkthe external wall of the perforator unit I0 which is adapted to cooperate with a tool to be used for assembling the respective units of the apparatus.

Within each cartridge chamber 20 is disposed a cartridge 2l, shown in greater detail in Fig. 6, which is adapted to be fired electrically as described in detail hereinafter. Referring to Fig. 6, the cartridge 2l comprises a metallic tubular casing 28, the front end of which is internally threaded at 29 to receive the externally threaded portion 30 of a conical closure member 3|. The rear end of the tubular casing 28 is provided with a closure member 32 within which is formed a circular aperture 33 tapering rearwardly to a restricted portion 34 which communicates with a larger circular recess 35 formed in therearface of the rear closure member 32.

The firing device for the cartridge 2l comprises an enclosed tubular casing 3B made of some low resistance material which contains a small amount of powder 31. The powder 31 is adapted to be ignited by a wire lament 38 which is connected at one end to aconducting rod 39 and at its other end to a conducting rod 4I). The conducting rod 39 extends through the tubular casing 36, through an aperture 4I in an ebonite plug 42 which is snugly tted against the rear closure member 32 and into the recess 35. Secured at the end of the conducting -rod 39 is a conical contact member 43 provided with a threaded portion 44 on which a second contact member 45 is adapted to be screwed.

The contact members 43 and 45 are maintained out of contact with the rear closure member 32 by an insulating disc 48 disposed between the rear face of the ebonite plug 42 and the rear face of the conical contact member 43 and by a ring lll oi insulating material which is inserted in the space between the second contact member 45 and the wall bounding the circular recess 35.

The conducting rod 4U extends through the other end of the tubular casing 36 and through a narrow bore 4B formed in the conical closure member 3l and it has a pointed end 49 which extends slightly beyond the forward extremity of the conical closure member 3l. A sleeve 59 of insulating material is iitted on the conducting rod 40 which serves to insulate the latter from the conical closure member 3l.

The pointed end 49' of the rod 40 of each cartridge 27 is adapted to bear against the contact member 45'l of the corresponding cartridge 21 oi' the next perforator unit I0', so as to insure electrical contact therewith. Electriccurrent can then flow through contact members 43 and 45, rod 39, lament 38, and rod 40 of perforator unit I0, to the cartridge 21' in perforator unit I0', and thus to the entire series of cartridges in the assembled apparatus.

In accordance with the invention, the perforator element I0 is provided with means i'or extracting the cartridges 21 from the cartridge chambers 20' of the adjacent lower pertorator unit I. The extracting means comprises a circular disc 52 provided with a plurality of spaced semi-circular notches 53 (Fig. 4), the centers of which are disposed at the apices of an equilateral triangle, within each of which av cartridge 21 is adapted to be received. To this end, an annular recess 54 is provided about the periphery of the rear closure member 32 of each cartridge 21 within which the semi-circular boundary of a notch 53 is adapted to be received.

The disc 52 is adapted to be secured to the lower face of the perforator unit I0 by means of a tap screw 55 which extends through a central bore 56 in the disc 52 into an internally threaded bore 51 in the perforator unit I0. The tap screw 55 is provided with a left-hand thread and the assembly is so designed that when it has been tightened up the disc 52 may be rotated freely about its axis.

In operation, three cartridges 21.' are inserted into the notches 53 in the extracting disc 52 and the latter is secured to the perforator unit I0 by means of the tap screw 55. The perforator unit I0 is then brought into proximity with the perforator unit IIJ', for example, and the cartridges 21 are inserted into the cartridge chambers 28' disposed therein. The externally threaded reduced portion 25 of the perforator unit I0 is then screwed into the internally threaded skirt portion 24 of the perforator unit IU'. Inasmuch t as the extracting disc 52 may rotate freely about the tap screw 55, this operation may be performed with facility.

After the cartridges 21 have been fired and the apparatus has been withdrawn from the bore hole, the perforator unit I8 is unscrewed from the perforator unit I8. Since the thread on the reduced portion 25 of the perforator unit is righthanded, whereas the tap screw 55 is provided with a left-hand thread, the latter cannot be unscrewed from the perforator unit I0 during this operation. Hence, as the unscrewing operation proceeds and the perforator unit I0 moves axially away from the perforator unit I0', the cartridges 21 are extracted from the cartridge chambers 28' and are retained by the extracting disc 52 from which they may be subsequently removed.

As indicated above, the uppermost perforator unit I0 is threadedly connected to a head piece I4 which includes means for connecting the firing circuits of the cartridges 21 to the conductors in the cable I6. Inasmuch as the three circuit connections in the head piece I4 are identical, it will be suficient to describe merely one.

Electrical energy for ring the cartridges 21 is supplied through the cable I6 which is provided with three conductors 58, 59 and 60 (Fig. 26), one for each series of cartridges 21 in the perforating apparatus. Each of the conductors 58, 59 and 60, respectively, is connected to a conducting rod 6I (Fig. 3) which extends through a passage 62 formed within the connector unit I8 and which is insulated therefrom by means of an insulating sleeve 63. 'I'he rod 6I extends through an insulating disc 64 disposed Within a. circular recess 65 formed by the cooperating adjacent ends of the connector elements I8 and I9, and its upper end is connected to a contact element 66 mounted within a recess 61 in a second insulating disc 68, also disposed within the recess 65. I

The contact element 66 is provided with a socket 69 within which a conducting rod 10 is adapted to be snugly received. The conducting rod passes through an aperture 1I in a third insulating disc 12 disposed on the top of the insulating discs 64 and 68. The three discs 12, 54 and 68 are held tightly in position by means of the tap screws 13 which are screwed into the threaded bores 14 in the connector eleirent I8. The conducting rod 18 extends through an insulating sleeve 15 within a narrow bore 16 in the connector element I9 and it terminates at its upper extremity in a point which is adapted to engage the contact member 45 on the cartridge 21 in the uppermost perforator unit I0, which is secured to the connector unit I9.

The connector unit I9 is also provided with means for extracting the cartridges 21 from the cartridge chambers 20 in the uppermost perforator unit II). This means is identical with'the means described above in connection with the perforator unit I0.

The lowermost perforator unit I0 is provided with a circular rotatable disc 24| which is secured thereto by means of the tap screw 55" which is adapted to be screwed into the threaded bore 51" in the lower portion of the perforator unit IIJ". The circular disc 24I is provided with three sectorshaped projections 242 which are adapted to engage the pointed ends 49" of the conducting rods 40 in the cartridges 21" in the lowermost perforator unit I0". The disc 24I is adapted to be maintained in close contact with the end piece II when the lowermost perforator unit I0" is screwed thereto and it is insulated from the lower face of the element Ill by a rubber disc 11.

A spindle 18 is screwed into a threaded bore 19 in the end piece II and it extends through a central bore in the guide member I2 which is secured thereon by means of a nut BI and a Washer 82 of the conventional type.

To assemble the perforating apparatus described above, the lowermost perforator unit Ill" is rst fixed upon a support. The cartridges 21" for the perforator unit I0 are then mounted in the extractor disc 52' of the next perforator unit I0' and the disc 52' is secured thereto by the tap screw 55'. The externally threaded reduced portion 25' of the second perforator unit I0 is then screwed into the internally threaded skirt portion 24" of the lowermost perforator unit I0". These operations are repeated until the perforator units I0, Ill and I8" have been assembled. Obviously, any number of units may be used.

The perforator units I0, Ill and I0" are so designed that, when assembled as indicated above, the cartridges 21 constitute three coaxially aligned groups. Each group of cartridges located along a generatrix of the apparatus constitutes an electric circuit extending over the entire length of the assembly, and there are three distinct electric circuits passing each through one of the three cartridge chambers 20 of each perforator unit.

The head piece I4 is then screwed in a similar manner on the uppermost perforator unit I0, thus connecting the three cartridge circuits to the three conductors 58, 59 and 60, respectively, in the cable I6. At this point the three cartridge circuits may be tested to determine if they are operative.

When the circuit tests have been successfully completed, the rubber disc 11 and the Contact disc 24I are secured to the lowermost perforator unit I0" by means of the tap screw 55", the position of the disc 24| being such that the projections 242 thereon are in engagement with the pointed ends 49" of the rods 4D" in the cartridges 21". The externally threaded reduced portion 25" of the perforator unit l" is then screwed into an internally threaded skirt portion 83 on the end piece H, so as to insure a good electrical contact between the disc 24| and the end piece Il.

As shown generally in Fig. 26, the conductors 58, 59 and 80 in the cable I6 are connected to the switches 84, 85 and 88, respectively, which are connected to the variable contact 81 of a rheostat 88. The rheostat 8B is connected to one terminal of a source of current 89, the other terminal of which is connected to ground 80, the circuit being completed through the earth and the conducting well fluid to the body of the device.

In operation, the completely assembled perforator, supported on the cable i6 is lowered into the bore hole, the casing of which is to be perforated. When the desired depth is reached, the switch 84, for example, is closed, causing current to flow from the source 88, through the rheostat 88, the switch 84, the conductor 58, and through the filaments 38, 38' and 38" of the cartridges 2l, 27' and 2l", respectively. The filaments 38, 38' and 38" are designed so that different current intensities are required to bring them to a red heat, the lowermost filament 38" being adapted to attain a red heat at the lowest current intensity.

The rheostat 88 is adjusted to give the current intensity required to bring the lowermost filament 38 to red heat, thus igniting the charge of black powder 3l in the casing 38". When the powder 37" is ignited, the combustion thereof bursts the casing 36" and thus transmits ignition to the explosive 5i present in the cartridge casing 28". The force of the explosion bursts the cartridge casing 28" at the barrel hole 28" and the powder gases released drive the bullet 238" out of the barrel hole 23".

At the time of the explosion, the ebonite plug 42" is liquefied by the heat and pressure to which it is subjected and it pushes the insulating disc 46 towards the rear so as to crush the metal contact member 43" against the rear closure member 32". The contact member 45 is now in electrical contact with the rear closure member 32" and with the metal of the perforator unit l0" in which the exploded cartridge 2l" is located. Since the pointed end 48' of the conducting rod 40' of the preceding cartridge 27 is now connected with the metallic mass of the apparatus the ring circuit remains closed and operative.

The rheostat 88 is then adjusted to increase the current intensity to the value required to bring the next filament 38' to a red heat. and the operations are continued until the required number of cartridges are red. The other two series of cartridges may be red in exactly the same manner.

Figs. 9 and 10 relate to another embodiment of a perforator unit I8 constructed according to the present invention, In this modification, the perforator vunit i8 is provided with a plurality oi' cartridge chambers Sla, Sib, 8Ic and Sid (four in the particular example shown by the drawings), the axes of which are symmetrically located therein with respect to two diametral planes located at right angles to each other. 'I'he cartridge chambers Sla, Sib, Slc and Qld are of the same general shape as those of the preceding embodiment.

The chief characteristic of the embodiment shown in Figs. 9 and 10 is that each cartridge chamber is provided with two barrel holes. For example, chamber Sla is provided with the barrel holes 82a and 82h; chamber 8lb has also two barrel holes 93a and 83h; chamber 9 Ic is provided with two barrel holes 94a and 84h; an-d chamber Qld has the barrel holes 95a and 95h.

It will be readily apparent that, since there is an even number of cartridge chambers diametrically opposed to one another, the barrels communicating with the chambers ycannot pass through the axis of the perforator unit I8. As shown by the drawings, two barrel holes associated with each chamber are located respectively in two planes passing through the axis of the cartridge chamber which are symmetrical to each other with reference to the diametral plane passing through said axis. For example, the respective axes of the barrels 92a and 92D of chamber 8la are located in two planes which are symmerically located with reference to the diametral plane passing through the axis of chambers Sla and Sic.

The construction and operation of a gun perforator having units of this kind is wholly analogous to that described with reference to the rst embodiment of this invention, with the diierence that the firing of each cartridge drives two bullets into the casing.

Fig. 7 shows another embodiment of a cartridge made according to the present invention. This cartridge is adapted to be fired automatically by means actuated by the powder gases produced in the corresponding cartridge of the preceding perforator unit. Accordingly, cartridges of this type may be used in any perforating unit except the unit l0 at the top, and they may be used in the unit Ill when mechanical tiring means of the type-shown in Fig. 28 is provided. The cartridge shown in Fig. 7 includes a tubular metallic casing 96' having a thin walled forward portion` 97' forming a main powder chamber 98 and a thicker walled rear portion 99' forming an auxiliary chamber Hi8 of lesser diameter.

The casing 96 is closed at its rear end by a transverse partition IM' in the rear face of which is formed a circular recess |02' which is adapted to receive a firing pin |03'. The ring pin |03 is provided with a conical portion [04' which is adapted to be projected through a small aperture |06' in the transverse partition mi against a metallic cup |06 insertedin a recess lill' formed in the transverse partition lill', which contains a small disc of mercury fulminate H88' or other similar detonating explosive.

Disposed within the auxiliary chamber |00 is a hollow tubular member |08 containing a slow fuse composition H0' and having an outwardly extending flange l I I which is screwed within the casing 96' adjacent the thicker walled rear portion 88'. The tubular member |08 is externally threaded and lt cooperates with ther auxiliary chamber |00 to form a labyrinth-like passage H2 which communicates with the main chamber 98' through a. plurality of apertures H3 formed in the ilange I l I' (Fig. 8). The' forward portion of the casing 86' is internally threaded at I I4' to receive an externally threaded conical plug H5' having a narrow axial bore H6 within which is disposed a pin Ill'. The forward end of the bore H6' is normally closed by a thin wall IIB which is adapted to be pierced by the pin II1 when the cartridge is red.

'I'he ilring of a group of cartridges -like the one described above may be initiated electrically or mechanically as shown in Figs. 27 and 28, respectively. In the electrically iired modication shown in Fig. 27, the rst cartridge in the well ner.

casing perforator unit I is provided with an igniting filament 24| imbedded in the charge of powder contained in the main powder chamber 98. The igniting filament 24| is grounded at one end to the metallic casing 96 of the cartridge and it is connected at its other end to a conductor 242 which is in engagement with the conducting rod in the connector element I9.

In operation, electric current is supplied to the lament 24| through the conducting rod 10 and the conductor 242. 'I'his produces an explosion which forces the pin in the bore IIS through the wall IIB against the ring pin |03' of the second cartridge. The impact forces the conical portion |04 of the ring pin |03' against the cup |06', thereby igniting the mercury fulminate |08' therein and simultaneously igniting the fuse composition IIO in the tube member |09.

The fuse composition I|0 now burns at a rate depending upon the ingredients from which it is made and these may be so chosen that the ignition of the explosive in the main powder chamber 98' will not take place until after a predetermined period of time has elapsed, corresponding to the interval which it is desired to produce between the ring of two successive cartridges. The gases produced by the burning of the composition ||0 ow into the auxiliary chamber I 00' through the labyrinth-like passage I2' and through the apertures I I3' into the main chamber 98. In traversing this path the gases are cooled to a considerable extent by expansion so that when they enter the main chamber 98' they are cool enough not to ignite the explosive 5| contained therein.

The combustion of the last remnants of the fuse composition ||0 will ignite the powder in the main chamber 98', the gases from which will ignite the third cartridge in an analogous man- In this fashion, all of the cartridges in this ignition path may be ignited successively.

If desired, the cartridge may be ignited mechanically by apparatus of the type shown in Fig. 28. In this iigure the cartridge is identical with the cartridge shown in Fig. 7 and corresponding parts have been designated by unprimed reference numerals. Referring to Fig. 28, the cartridge is shown disposed in one of the powder chambers in the well casing perforator. Within the connector element I9a, to which the perforating unit I0 is secured, there is formed a longitudinal bore 243 within which is disposed a i'lring pin 244, the lower end of which rests against the firing pin |03 of the cartridge.

When it is desired to ignite the cartridge in the chamber 20, a suitable weight 245 is dropped into the bore hole on the cable Ilia by means of which the apparatus is suspended therein. The

weight 245 eventually strikes the ring pin 244, driving it forcibly against the firing pin |03 and igniting the cartridge essentially as described above in connection with Fig. 27.

'Ihe embodiment illustrated in Figs. 11 and 11A of the drawings features only two cartridge chambers ||9A and HSB, in each perforator unit I0, the axes of which are located in a common diametral plane. In this embodiment of the invention the barrel hole communicating with each cartridge chamber does not extend straight from the wall of the perforator unit, but is bent so that its main portion in which the bullet is -2'I in the uppermost perforator element plane at right angles to the diametral plane of the axes of the two chambers.

For example, the cartridge chamber I ISA communicates with a bent passage |20A which terminates in a barrel hole |2IA extending between the two chambers |I9A and I|9B and at right angles to the common plane of their axes. An important feature of this modiflcation, and of the modication described above, is that it provides a maximum barrel length enabling the bullet to pass through a .relatively great distance before it is projected into the casing.

Fig. 12 illustrates a modified form of connector unit which is adapted to break a ring circuit each time a Ibullet is red, thereby indicating to an operator at the surface that the firing operation has been successful. The general structure of the connector unit shown in Fig. 12 is analogous to that of the units |8 and I9 shown in Fig. 3 except that each of the conducting rods 6| is secured within a recess |22 in a conducting block |23 by means of a tap screw |24. The block |23 is insulated from the connector unit |25 by means of the insulating material |26.

The tap screw |24 is electrically connected through a wire |21 to one contact element |28 of a conventional type mercury switch |29 which is vertically disposed within a rubber sleeve |30, and which contains just enough mercury to remain in contact with the contact unit |28 when the connector unit |25 is at rest. The other contact element |3| of the switch |29 is connected by means of a conductor |32 to a conductive block |33. The block |33 is connected by means of the conductors |34, |35 and |36 to the conducting rod 10 which is adapted to engage the contact member 45 on the cartridge 0 (Fig. 3).

When the assembled perforator is at rest, the contact element |28 dips into the mercury in the switch |29 so that electric current flows normally therethrough to the iiring circuit. However, when a shot is red, the entire perforator assembly susrains a violent shock which displaces the mercury in the switch |29, thereby temporarily breaking the electrical ring circuit.

The break in the circuit may be readily indicated in any suitable manner, as, for example, by means of a receiver at the surface of the earth which is connected in series with the ring circuit. In this fashion. it is possible to check the ring of the shots by noting the breakin the electrical circuit produced by the shock sustained by the perforator assembly.

Figs. 13, 13A and 14 illustrate a further modication of perforator unit l0 in which three cartride chambers I3'IA, |3'IB and I3`|C are provided, the axes of which' are located parallel to the axis of the perforator unit I0, forming the respective edges of an equilateral prism coaxial thereto. In this embodiment the cartridge chambers |31A, |3'IB and I3'IC are provided at their lower extremities with the longitudinally extending conduits |38A, |38B and |38C, respectively, which communicate with the laterally extending barrel holes |39Ay |39B and |39C, respectively.

It will be noted th'at the conduits |38A, 38B and |380 are made of diierent lengths so that the barrel holes |39A, |39B and |39C lie in diierent transverse planes. As shown in greater detail in Fig. 13. the barrel holes I39A, |39B and |39C are adapted to be received is located in a diametral located in radial planes which are disposed at an angle of 120 with respect to each other.

It will be apparent that in this modification the electrical ring circuit cannot extend longitudinally throughout each cartridge as in the preceding embodiments. Accordingly. it is necessary to provide a special firing circuit as indicated in Fig. 14.

Referring to Fig. 14, a cartridge |40 is shown in position in the cartridge chamber- I31B, for example, and it is provided with a thin Walled forward portion |4| forming a main powder chamber |42 and a thicker walled rear portion |43 forming a passage |44. The front end of the cartridge is closed by a suitable closure member |58. Within the passage |44 is disposed a hollow tubular conducting member |45 which is provided with a metal plate |46 at the lower extremity thereof, the outer surface of both the plate |46 and the tubular member |45 being covered with suitable insulating materia1 |41,

Disposed within the tubular member |45 and concentric therewith is a conducting rod |48 which extends for a short distance beyond the tubular member |45 into the chamber |42 of the cartridge |40, and which is provided at its lower extremity with a metal plate |49, the surface of the metal plate |49 and the conducting rod |48 being encased in suitable insulating material |50. A wire filament |5| for igniting the powder within the chamber |42 is connected at one end to thehgqr tubular member |45 and at the other end to the conducting rod |48 and the energizing circuit is 'traced through the conducting plate |49, conducting rod |48, wire filament|5|, the tubular conducting member |45 and` the plate |46.

Within the perforato'r unit |0 are provided three longitudinally extending bores |52, the axes of which are disposed substantially at the apices of an equilaterial triangle, each of which is adapted to accommodate a conducting rod |53, respectively. The rods |53 are provided with pointed .ends which project slightly beyond the front and rear faces of the perforator unit and they are insulated from the perforator unit I0 by sleeves of insulated material |54.

As shown in greater detail in Fig. 13A, each of the conducting plates |49 is provided with a projecting portion |55, and each conducting plate |46 is provided with a similar projecting portion |56. The cartridge |40 is so assembled that the projection |55 on plate |49 is disposed substantially 180 away from the projection |56 on the plate |46 and it is inserted into the cartridge chamber |31B in such fashion 'that the projection |56 on plate |46 is disposed adjacent the pointed end of one of the rods |53.

The perforator units are so designed that when the element |0", for example, is screwed into the unit |0, the pointed end of the conducting rod |53' of the perforator unit |0" pierces the insulating layer |50 covering the projection |55 of the conducting plate |49 while the pointed end of the conducting rod |53 of the perforator unit l0 pierces the insulating layer |41 which covers the projection |56 of the conducting plate |46.

It will be apparent, therefore, that current flowing from the conducting rod |53' of the preceding perforator unit |0"' will pass through the conducting plate |49, the conducting rod |48, the filament |I, the tubular conducting member |45, the conducting plate |46 and the conducting rod |53 of the perforator unit |0,to th'e contact plate |49' of the next perforator unit I0. In this fashion current is supplied to each series of cartridges |40 in the assembled perforator.

It will be noted further -that in this embodiment the transmission of current does not take place along the same generatrix of the perforator. On the contrary, the current path is along one generatrix in the perforator unit l0, then along a generatrix located at an angle of approximately 115 away on the next succeeding perforator unit I0', and so on through the respective units of the assembled apparatus.

In order that the cartridges may be readily inserted within the respective cartridge ch'ambers, the internally threaded skirt portion 24 of each perforator unit l0 may be suitably notched, as, for example, at |51.

In operation, the current through each filament |5| is adjusted as indicated above with reference to Fig. 26 until it is of sufcient intensity to ignite the powder 'contained within the cartridge |40. When this occurs the pressure of the gases ruptures the forward closure member |58 of the cartridge |40, thereby forcing the projectile 239 out of the barrel hole |39B.

"As soon as the projectile 239 has left the barrel hole |39A, the liquid usually present in the bore casingflows through the barrel 39B and the passage |38B into the main chamber |42 of the cartridge |40 so that the firing circuit which was broken by the destruction of the filament |5| is now completed through the liquid. In addition, the destruction of the insulating material |41 and by the explosion has the effect of grounding the broken end of the ring circuit to the mass of the assembled apparatus.

Figs. 15 and 16 illustrate another embodiment of the invention in which ignition is automatically transmitted from one cartridge to another cartridge located along a different generatrix, the radial plane of which makes a given angle with the radial plane of the generatrix corresponding to the preceding cartridge. In this embodiment each cartridge 238 is provided with a forward closure portion |59 having a very narrow bore |60 formed therein. The bore |60 is adapted to register with a narrow inclined passage |6| formed in the perforator unit I0, which extends to the cartridge 238 located on a different generatrix in the next perforator unit I0.

In this embodiment when the cartridge 238 is fired the powder gases pass through the narrow bore |60 in the forward closure member |59 of the cartridge 238 to the inclined passage |6| where they are allowed to expand. The expanded gases then pass to the rear end of the cartridge 238' in the next perforator element I0'. Here the gases flow through a, restricted aperture |62', and through a passage |63' to the powder contained within the cartridge 238 which is ignited thereby.

The passage through the restricted bore |60 and the subsequent expansion in the inclined passage |6| produces a delay in the transmission of ignition so that a certain interval of time elapses between the firing of the successive cartridges. The firing of the cartridges in this embodiment is eifected by using in the first perforator unit l0 an electrically or mechanically ignited cartridge similar to those shown in Figs. 27 and 28.

In the embodiment shown in Fig. 17, the cartridge |64 is provided with a rear closure member |65 having a passage |86 therein within which is disposed an insulating sleeve |61 having a contact rod |68 therein. In this modification an extractor disc" |69 is used which is provided with threaded recesses |10 within which the rear closure members |65 of the cartridges |64 for`the next perforator unit I0' are adapted to be screwed. Each threaded recess communicates through a narrow passage I1| with a larger sector-shaped recess |12 formed in the lower face of the extractor disc |69 within which is adapted to be received a metallic plate |13 of approximately the same shape, which is enclosed in insulating material |14.

As shown in Figs. 20 and 21, a small portion of the insulation is removed from the lower face of the plate |13 forming a slot |15 and part of the insulation is removed. from the upper face of the plate |13 to form a small hole |16, which is adapted to register with the narrow passage |1| in the disc |69 when the plate |13 is disposed in the recess |12 formed therein.

The cartridge |64 is provided with a forward closure member |11 made of insulating material in which is inserted a conducting rod |18. The conducting rod |18 is enclosed in a sleeve |18 of insulating material within a passage |80 in the perforator unit I0 and it is provided with a pointed end which is adapted to project through the slot |15 into engagement with one of the plates |13 in the extractor disc |69. A wire lilament 243 is connected between the contact rod |68 and contact rod |18 which serves to ignite the powder in the cartridge |64.

When the perforator units I0", I0 and I0' are assembled as in Fig. 17, it will be noted that the contact rods |18" of the cartridges |64" in perforator unit |0 extend through the lower slots |15" in the insulation |14" into engagement with the contact plates |13", and that the contact rods |68 of the cartridges |64 in the perforatcr unit I0 project through the upper holes |16" into engagement with the contact plates |13", as shown in Fig. 18. Similar connections obtain between the perforator units |0 and l0', as indicated in Fig. 19, so that three continuous firing circuits are produced in the assembled perforator.

It Will be apparent that in this modification the successive cartridges |64 through which the ring current passes are located -in different radial planes, the angle between the two successive radial planes being approximately equal to the angle subtended by the contact plate |13.

In all of the embodiments described above, three or more electrical circuits in the assembled perforator are electrically connected to three or more conductors in the cable I6. If desired, however, a single conductor might be used, together with mechanism as indicated in Figs. 22 to 25, inclusive, which is adapted to connect the cable successively to each of the circuits in the perforator assembly. These modifications are designed to switch the connection automatically from one series of cartridges to the next whenever a shot is fired.

Referring to Fig. 22,*the connector unit I8 is formed with a shouldered portion |8|, on which a metallic sleeve |82 is adapted to be rotatably mounted. Within the lower portion of the sleeve |82 is disposed an insulating sleeve |83 in which is embedded a conducting ring |88. The conducting ring |84 is electrically connected through a conductor |85 to a conducting sector |86 which is also embedded in the insulating material |83.

The conducting ring |86 is maintained in engagement with a contact lrod |81 which is electrically connected to an axial conducting rod |98 connected at its upper extremity to a conductor sa in the cable le. The conducting rod |91 is insulated from the mass of the perforatorl unit by an insulating sleeve |89 and the axial conducting rpd |88 is insulated in a similar manner by an analogous insulating sleeve |80. Each of the conducting rods 10 which carry current to the respective cartridge circuits, has secured thereto a radially extending contact rod |8| which is disposed within an insulating sleeve |92 and which is adapted to engage the contact sector |86 as the sleeve |82 is rotated with respect to the connector unit |8.

The connector unit I8 is provided with a portion |93 of reduced diameter on which is disposed a coil spring |94, one end of which is secured to the connector unit I8 at the point |95 and the other end of which is secured to a link |91 which is connected to the rotatable sleeve |82 at the point |96. The spring |94 tends to rotate tle sleeve |82 with respect to the connector unit The rotatable sleeve |82 is provided with a plurality of longitudinal extending teeth |98 which are adapted to be received in corresponding recesses |99 formed in a sleeve 200 which is carried on the connector unit I8 so as to be slidable axially without rotation thereupon. The sleeve 200 is4 normally urged downwardly by means of a coil spring 20|, thereby engaging the teeth |88 on the sleeve |82 in the recesses |99 provided in the sleeve 200, and locking the sleeve |82 in position. Mounted on the sleeve 200 is a rubber ring 202 which is of substantially the same diameter as the diameter of the bore hole.

Before a cartridge may be fired, the position of the sleeve |82 with respect to the connector unit |8 must be such that one of the contact rods |9| is in engagement with the sector |86. When this condition obtains, a circuit is completed from the conductor 58 through the conducting rod |88, contact rod |81 engaging contact ring |84, conductor |85, contact segment 86 engaging contact rod |9|, and contact rod 10 to a cartridge circuit.

When a cartridge in this circuit is red the powder gases issuing from the corresponding barrel exert an upward thrust on the ring 202, thereby causing the teeth |98 to become disengaged from the recesses |99 and permitting the sleeve |82 to rotate with respect to the connector unit I8. However, as soon as the energy in the gases has been dissipated the spring 20| returns the sleeve 200 to its normal position, thereby engaging the teeth |98 in the recesses |98 and again holding the sleeve |82 in xed position.

The tensions in the springs |94 and 20| are such as to permit the sleeve |82 to rotate through a sufficient angle after it has been released to move the sector |86 out of engagement with the rod |9| and into engagement with the rod |9| of the circuit corresponding to another group of cartridges.

In the modification shown in Fig. 23, the conducting rod |88 which is in electrical connection with the conductor 58 of the cable I6 terminates in an enlarged portion 203, the lower surface of which is curved at 204 and which is adapted to engage a spherical conducting ball 205. The conducting ball 205 rests upon a cup-shaped member 206 provided with a tubular shaft 201 which is movable axially in a bushing 208 secured within a tubular member 209 fixed to the connector unit i8, and insulated therefrom by an insulating sleeve 244.

The tubular element 208 is provided with an outwardly extending ange 2|0 at the lower extremity thereof which is adapted to seat a com pression spring 2|I, the upper end of which is seated in an annular recess 2|2 formed in the lower face ofthe cup-shaped member 206, thereby maintaining the spherical ball 205 in good electrical contact with the enlarged portion 203 of the conducting rod |88.

At the lower end of the tubular portion 201 on the cup-shaped member 206 is fitted a contact plate 2I3 which is continually engaged by the actuator 2|4 of a commutating switch 2|6. The actuator 2|4 is made of conductive material and it serves to complete the circuit from the conducting plate 2|3 to one element of the switch 2|8. The switch 2|6 is adapted to connect the conducting rod |88 selectively to the various conducting rods corresponding to the respective groups of cartridges in the assembled perforator.

In operation, when a cartridge is red, the impact moves the spherical ball 205 laterally relatively to the perforator assembly thereby moving the cup-shaped member 206 axially against the force of the compression spring 2| I. This action depresses the actuator 2I4 of the switch 2|6 thereby connecting the conducting rod |88 to the next series of cartridges which are to be fired.

The modification illustrated in Fig. 24 is similar to that shown in Fig. 23 except that the spherical ball 205 is replaced by a cylindrical conducting mass 2|1 which is elastically suspended in the connector unit I8 by suitable supports 2|8 made of resilient material, such as, for example, rubber. In this modification the switch 2| 6 is provided with an extended actuator 2|9 which projects into a conical recess 220 formed in the lower face of the cylindrical mass 2I1. As in the previous case, when the gun is red, the mass 2|1 is moved laterally and the conical recess 220 therein depresses the switch actuator 2|9, thereby disconnecting the conducting rod |88 from one cartridge circuit and connecting it to a different cartridge circuit.

The modification shown in Fig. 25 is similar to that shown in Fig. 22. In this embodiment, however, the sleeve |82 is adapted to be rotated with respect to the connector unit I8 by means of a coil spring 22| which is secured on the connector unit I8 at the point 222. The interior wall of the sleeve |82 is provided with a plurality of spaced recesses 223 within which a transversely extending rod 224 is adapted to be received for the purpose of holding the sleeve |82 in fixed position. The rod 224 is continually urged into engagement with the recess 223 by means of a compression spring 225, the lower end of which is seated within an annular recess 226 formed in the wall of the connector unit I8 and the upper end of which is seated against a disc 221 secured to the rod 224.

A large mass 228 is suspended within the connector unit I8 on an elastic cable 229 and it is connected at its lower end by means of a cable 230 to one arm 23| of a bell crank mechanism 232 which is pvoted at 233. The other arm 234 of the bell crank mechanism 232 is provided with a slot 235'Within which a pin 236 on the rod 224 is adapted to be received. The conducting rod |88 which supplies current to the cartridges is connected by means of a conductor 231 to an insulated conducting rod |81 which is maintained in contact with the conducting ring |84 in the sleeve |83.

In operation, when the gun is red, the shock imparted to the periorator assembly causes the mass 228 to move laterally within the connector unit 8. In so moving the mass 228 causes the bell crank mechanism 232 to pivot about the point 233, thereby moving the arm 234 downwardly and disengaging the rod from its recess 223. This permits the sleeve |82 to rotate under the influence of the compression spring 22| through a sufficient distance to bring the conducting sector |88 into engagement with the conducting rod 10 corresponding to the next cartridge circuit which is to be energized. By this time the weight 228 has returned to its normal position and the rod 224 is again moved into engagement with a recess 223 by the compression spring 225.

While several specific embodiments have been described above, the invention is not intended to be in any way limited thereby but is susceptible of numerous changes in form and detail within the scope of the appended claims.

I claim:

Vl. A well casing perforator which comprises at least one body member provided with at least two distinct powder-chambers extending substantially longitudinally therein and located in peripheral regions thereof with their transverse axes in close proximity to each other, and means forming at least one barrel hole extending from each of said chambers to the outer wall of said body member and passing through the central portion thereof.

2. A well casing perforator which comprises at least one body member provided with at least two distinct powder-chambers extending substantially longitudinally therein and located in peripheral regions thereof with their transverse axes lying substantially in a common transverse plane, and means forming at least one barrel-hole for each of said chambers extending from the lateral wall of the chamber transversely of the body member and passing through the central portion thereof.

3. A well casing perforator which comprises at least one body member having a longitudinal axis provided with at least two cartridge chambers extending therein with their axes parallel to said longitudinal axis and located in peripheral regions of said body member, and means forming at least one barrel hole for each of said chambers extending in said body member transversely of its axis and passing through the central portion of said body member.

4. A Well casing perforator which comprises at least one body member having a longitudinal axis provided with at least three powder chambers extending therein parallel to the axis of the body member and located in peripheral regions thereof, and means forming at least one barrel hole for each of said chambers extending through said body member in a straight line transversely of its axis and passing through the central portion of said body member.

5. A well casing perforator which comprises at least one body member having a longitudinal axis provided with at least three cartridge chambers having their axes parallel to said longitudinal axis .and passing through the apices of a regular polygon located in a plane at right angles to said longitudinal axis and means forming at least one barrel hole for each of said chambers extending through said body member inY a straight line transversely of its axis and passing through the central portion of said body member.

6. A well casing perforator which comprises at least one body member having a longitudinal axis, provided with at least three powder chambers extending therein substantially parallel to said longitudinal axis and located in peripheral regions thereof, and means forming at least two straight barrel holes for each of said chambers, extending transversely of said body member adjacent the axis thereof but o n opposite sides thereof, respectively.l

7. A well casing perforator which comprises at least one body member having a longitudinal axis, provided with at least three cartridge chambers having their axes parallel to said longitudinal axis and located in peripheral regions of said body member, means forming at least two straight barrel holes for each of said chambers, extending transversely of said body member adjacent the axis thereof but on opposite sides thereof. respectively.

8. A well casing perforator comprisingy at least one body member having a longitudinal axis, provided with two powder chambers extending therein substantially parallel to said longitudinal axis,

l and located in a diametral plane on either side of the axis of said body member, and means forming at least one barrel hole for each of said chambers, extending from the chamber to the outer wall of the body member, each barrel hole having a curved portion and a longer straight portion located in a diametral plane at right angles to the diametral plane of the powder chambers.

9. A well casing perforator which comprises at least one body member having a longitudinal axis,

. provided with ltwo cartridge chambers having their axes parallel to said longitudinal axis and being located in a diametral plane on either side of the axis of said body member, respectively, and means for-ming one barrel hole extending from the lateral wall of each of said chambers to the outer wall of said body member, each of said barrel holes having a curved portion and a longer straight portion extending in a diametral plane at right angles to the diametral plane of the powder chambers.

in combination a plurality of interchangeable r units detachably assembled to one another in consecutive series in a longitudinal direction, each unit being provided with at least one powder chamber and at least one barrel hole for said chamber, and electric igniting means in each of said units for igniting the powder in the chamber therein, said means being adapted to be interconnected automatically from one unit to Ithe next one upon assembly of said units so as to constitute atleast one ignition circuit extending therethrough.

12. A well casing perforator which comprises in combination a plurality of interchangeable units detachably assembled to one another in consecutive series in a longitudinal direction, each unit being provided with at least one longitudinal powder chamber and at leastone barrel hole for said chamber, an igniting filament in each of said chambers, and an electric circuit element extending throughout said unit including said filament, said circuit being adapted to be automatically connected to the corresponding circuit elements of the two adjacent units. upon assembly thereof, so as to constitute at least one ignition circuit extending therethrough.

13. A well casing perforator which comprises in combination a plurality of interchangeable units detachably assembled to one another in consecutive series in a. longitudinal direction, each unit being provided with at least one longitudinal powder chamber extending throughout the unit, and at least one barrel hole for said chamber, an electric circuit element, including an igniting filament extending longitudinally throughout each of said chambers, said electric circuit elements being adapted to be automatically interconnected, from one unit to the next, upon assembly of said units, so as to constitute at least one complete ignition circuit extending therethrough.

14. A well casing perforator which comprises in combination a plurality of interchangeable units` detachably assembled to one another in consecu-tive series in a longitudinal direction, each unit being provided with at least one longitudinal cantridge chamber and at least one barrel hole for said chamber, a cartridge in said chamber containing powder, an igniting filament in said cartridge, an electric circuit element, including said filament, extending longitudinally throughout each of said units for igniting the powder in said cartridge, said electric circuit elements being adapted to be automatically interconnected from one unit to the next upon assembly of said units so as to constitute at least one complete ignition circuit extending therethrough.

l5. A well casing perforator which comprises in combination a plurality of units detachably assembled to one another in consecutive series in a longitudinal direction, each unit being provided with at least two longitudinal powder chambers extending each throughout said unit and at least one barrel hole for each chamber, and electric igniting means extending longitudinally through each of said chambers, the igniting means of onel unit being adapted to be automatically connected with the corresponding means of the next unit, respectively, upon assembly of said units, so as to constitute at least two distinct ignition circuits extending therethrough.

16. A well vcasing perforator which comprises in combination a plurality of interchangeable units detachably assembled to one another in consecutive series, each unit being provided with at least two powder chambers and at least one barrel for each of said chambers, and igniting means in each of said units for igniting the powder in said chambers, said means being adapted to be automatically interconnected from one unit to the next one upon assembly of said units so as to constitute at least one ignition circuits extending therethrough.

17. A well casing perforator which comprises in combination a plurality of units detachably assembled together in consecutive series in a longitudinal direction, each unit being provided with at least one longitudinal cartridge chamber opening into one end face of said unit and at least one barrel hole for said chamber transverse to said longitudinal direction, a cartridge fitting in said chamber including a tubular case closed at both ends, powder in said tubular case, metallic contact means carried by the rear end part of said case and normally out of contact therewith, electric conductor means extending from said contact means into said case and throughout said unit so as to be connected, upon assembly of said unit with the next one, with the contact means of the corresponding cartridge `of said next unit, and a filament inserted in series in said conductor means inside said first mentioned cartridge, said contact means being adapted to be crushed by the pressure of the explosion gases into contact with said rear end part of the cartridge case,

so as to afford direct electrical connection with 'of said chambers including a tubular case closed at both ends and fitting in said chamber, powder in said tubular case, metallic contact means housed in the rear end part of said case and normally out of contacttherewith, electric conductor means extending longitudinally throughout said case from said contact means and including a rod projecting from the front end of the cartridge, said unit being provided with a holel for said rod, so as to enable said rod to bear on the contact means of the corresponding cartridge of the next unit and a iilament inserted in series in said conductor means inside said cartridge, said contact means being adapted to be crushed by the pressure of the explosion gases into contact with said rear end part of the cartridge, so as to afford direct electrical connection with the metal of the unit after the explosion of the cartridge.

19. A well casing perforator which comprises in combination a plurality of metal units detachably assembled together in consecutive series in a longitudinal direction, each unit being provided with at least two longitudinal cartridge chambers opening into one end face thereof, and at least one barrel hole for each of said chambers disposed transversely of said longitudinal direction, said units being so disposed that, when assembled together, their cartridge chambers are located along two longitudinal lines, respectively, the cartridge in each of said chambers including a tubular case closed at both ends and fitted in said chamber, powder in said tubular case, metallic contact means housed in the rear end part of said case and normally out of contact therewith, electric conductor means extending longitudinally throughout said case from said contact means and including a rod projecting from the front end of the cartridge, said unit being provided with a hole for said rod, so as to enable said rod to bear on the contact means of the corresponding cartridge of the next unit, a filament inserted in series in said conductor means inside said cartridge, said contact means including a tubular metal element housed in said' rear end part of said case with an insulating annular spacing therebetween, and a plug interposed between said contact means and the powder in said case made of a matter adapted to be melted by the temperature and pressure of the powder gases to crush said tubular metal element into contact with said rear end part of said case, so as to afford direct electrical connection with the metal of the unit after the explosion of the cartridge.

20. A well casing perforator which comprises in combination a plurality of units detachably assembled together in consecutive series, each unit being provided with at least one longitudinally extending cartridge chamber, having an opening at one end of said unit, means forming at least one barrel hole for said chamber extending transversely of the unit and extracting means carried by each unit for removing `a cartridge from the chamber of the next unit when said two last mentioned units are separated from each other.

21. A well casing perforator which comprises in combination a plurality of interchangeable metal blocks adapted to be screwed one to the other in consecutive series in a longitudinal direction, each block being provided with at least one longitudinal cartridge chamber open at one end of said block, at least one barrel hole for said cartridge chamber transverse to said'longitudinal direction and extracting means carried by each block and engaging the cartridge `of the next block adapted to extract said cartridge from the last mentioned block when it is unscrewed from the other.

22. A well casing perforator which comprises at least one body member having a longitudinal axis, provided with at least three cartridge chambers having their axes parallel to said longitudinal axis and passing through #the apices of a regular polygon and means forming at least one straight barrel hole for each of said chambers extending through said body member transversely thereof and intersecting the axis thereof.

23. A well casing perforator which comprises at least one body member having a longitudinal axis provided with three cartridge chambers having their axes parallel to said longitudinal axis and passing through the apices of an equilateral triangle and means forming at least one straight barrel hole for each of said chambers extending transversely of said body member and intersecting the axis thereof, said barrel holes being located in different transverse planes respectively.

24. In a gun perforator: a gun body having a pair of oppositely directed gun bores intersecting its side walls, and axially oppositely directed cartridge bores intersecting the inner ends of said gun bores and the axial extremities of said gun body; bullets for said gun bores; cartridges for said cartridge bores; and sealing means closing said cartridge bores.

25. In a gun perforator: a gun body having a pair of laterally and diametrically oppositely directed gun bores offset axially from each other and occupying the major portion of the gun body diameter and an individual cartridge chamber extending from each end of each gun body toward each other parallelA to but offset from the axis of said gun body and from each other and intersecting the inner end of a corresponding gun bore; bullets for said gun bores; cartridges for said cartridge chambers; and an explosive-resistant plug closing said cartridge chambers.

MARCEL SCHLUMBERGER. 

